If you're migrating from Oracle to InterSystems IRIS—like many of my customers—you may run into Oracle-specific SQL patterns that need translation.

Take this example:

SELECT (TO_DATE('2023-05-12','YYYY-MM-DD') - LEVEL + 1) AS gap_date
FROM dual
CONNECT BY LEVEL <= (TO_DATE('2023-05-12','YYYY-MM-DD') - TO_DATE('2023-05-02','YYYY-MM-DD') + 1);

In Oracle:

It helps to remove special characters, such as non-utf-8 characters either control characters or unicode characters from text that is not printable or can't be parsed by downstream systems.

There is also $C(32) in this condition; sometimes NBSP appears in the text and it will not be recognized by TIE, but downstream it displays as "?".

Motivation

I didn't know about ObjectScript until I started my new job. Objectscript isn't actually a young programming language. Compared to C++, Java and Python, the community isn't as active, but we're keen to make this place more vibrant, aren't we?

I've noticed that some of my colleagues are finding it tricky to get their heads around the class relationships in these huge projects. There aren't any easy-to-use modern class diagram tool for ObjectScript.

Related Work

I have tried relavant works:

InterSystems FAQ rubric

You can use the WriteToConsoleLog method of the %SYS.System class to write any message to the console log.

The following is an example:

Hi Community,

In this article, we will explore the concepts of Dynamic SQL and Embedded SQL within the context of InterSystems IRIS, provide practical examples, and examine their differences to help you understand how to leverage them in your applications.

InterSystems SQL provides a full set of standard relational features, including the ability to define table schema, execute queries, and define and execute stored procedures. You can execute InterSystems SQL interactively from the Management Portal or programmatically using a SQL shell interface. Embedded SQL enables you to embed SQL statements in your ObjectScript code, while Dynamic SQL enables you to execute dynamic SQL statements from ObjectScript at runtime. While static SQL queries offer predictable performance, dynamic and embedded SQL offer flexibility and integration, respectively.

Host Variables are a rather common programming feature in many implementations of SQL.
A recent question in DC made me aware that in IRIS, Caché, Ensemble, ...
host variables just exist within embedded SQL

> You can supply host variables for Embedded SQL queries only. <

Related examples are included in the available Documentation

This is a description for a workaround if you don't / can't use embedded SQL.

I recently met an ages old issue related to code maintenance:

• You have access to your IRIS server just over ODBC/JDBC
• no VSCode access, no Studio access
• no (Web-)Terminal access

But you need to take a look on Classes or Routines or Globals !!
Anyhow SQL is your friend.

InterSystems FAQ rubric

If you want to raise an arbitrary custom error in a TRY block, you can pass an exception with a throw as follows. In the following example, a custom error is raised if Stcount is less than 1.

InterSystems FAQ rubric

Mirroring only synchronizes database files.

To synchronize other files required for your application (CSP files, images, documents, etc.) between the two servers that make up the mirror set follow one of the approaches:

1. Place those files on a shared disk by introducing a NAS or similar device
2. Or use file sync software to synchronize files between two servers.

InterSystems FAQ rubric

You can check the free disk space at any time using the system utility class: SYS.Database and query: FreeSpace.

InterSystems FAQ rubric

The location of the currently executing code can be obtained using the $STACK function: $STACK($STACK,"PLACE").

Please refer to the following document for sample code.

InterSystems FAQ rubric

In SQL, NULL data and the empty string ('') are different data. The method for setting and checking each is as follows.

(1) NULL data

[SQL]

InterSystems FAQ rubric

Temporary globals stored in the IRISTEMP/CACHETEMP databases are used when a process does not need to store data indefinitely, but requires the powerful performance of globals. The IRISTEMP/CACHETEMP databases are not journaled, so using temporary globals does not create journal files.

The system uses the IRISTEMP/CACHETEMP databases for temporary storage and are available to users for the same.